Stop mechanism for loopers



19, 1936. T. H. DE SPAIN STOP MECHANISM FOR LOOPERS Original Filed Oct. 15, 1934 2 Shets-$heet l 1936- T. H. DE SPAIN 2,041,673

STOP MECHANISM FOR LOOPERS Original Filed Oct. 15, 1954 2 Sheets-Sheet 2 gnaw/m 7710771115 [7. DeSp Ln Patented May 19, 1936 UNITED STATES PATENT OFFICE STOP MECHANISM FOR LOOPERS Original application 748,401. Divided October 15, 1934, Serial No. and this application February 4, 1935, Serial No. 4,932

4 Claims.

This invention relates to sewing mechanisms and particularly to a stop motion device for such mechanisms.

One object is to provide a stop motion device which will serve as a detector for any number of threads or thread ends that may be used in the sewing operation.

More specifically, the invention contemplates a stop motion device for the sewing mechanism of machines commonly known as dial loopers wherein two sewing instrumentalities are used,

. i. e., a thread needle and a looper and the present device is especially designed for use where a plurality of ends are fed individually to both the needle and the looper.

A further object is to provide a stop motion device of comparatively simple design and which will be positive in operation.

With these and other objects in view, the invention consists in certain details of construction and combinations and arrangements of parts, allas will hereinafter be more fully described, and the novel features thereof particularly pointed out in the appended claims.

In the accompanying drawings- Figure 1 is a top plan view of a dial looper, illustrating the present stop motion device and its association with the drive shaft of the machine;

Fig. 2 is a perspective view illustrating the clutch shifter connections and the thread detectors;

Fig. 3 is a vertical sectional view on the line 3-3 of Fig. 1, taken longitudinally of the shaft on which the detectors are pivoted;

Fig. 4 is a sectional view on the line 4-4 of Fig. 1; and

Fig. 5 is a similar view on the line 5-5 of Fig. 1.

As before mentioned, the present invention is especially applicable to dial loopers and for this reason it is illustrated in the present instance in connection with such a machine. For a full description of a machine of this type, reference is made to applicants copending application, Serial No. 748,401, filed October 15, 1934, of which the present application is a division. For present purposes, suffice it to say that the rotating dial carrying the work points I is revolved by operating connections comprising gears H, I 2, the latter being mounted on a shaft l3 driven from the main drive shaft I 4, to which power is supplied from any suitable source. The sewing needle (not shown) is mounted in a needle arm I and is actuated by cam IS on the main drive shaft through lever l1 to impart a lateral or stepover movement to said needle and a cam IS on the drive shaft operatively connected to said needle arm by link l9 reciprocates or oscillates said needle. The looper (not shown) is actuated by connections comprising a cam 20 on the drive shaft. 5

In the event a thread breaks or becomes depleted, it is essential that the operation of the sewing mechanism, i. e., the needle and the looper, cease. This is, of course, also true where two or more separate or individual ends are fed 10 to the needle and/or looper, as, for instance, where knitted fabrics having loops or stitches with large openings are being united, in which case a comparatively large thread must be used in order to eliminate the presence of openings or interstices in the finished seam. In the present illustration, the machine is of the latter type, being equipped with a plurality of guides 2|, 22, 23, for thread ends for the needle and guides 24, 25, 26 for the thread ends for the looper. Two needle thread ends N N and a corresponding number of looper thread ends L L are shown. The drive shaft I4 is provided with a clutch 21 movable to its operative and inoperative positions by clutch shifting mechanism comprising 25 a clutch shifter rod 28 attached to a lever 29 pivoted at 30 and operatively connected to the clutch shifting ring 3| by a cam roller 32 engaging a cam surface 33 on said ring. The clutch is shown in the present instance in operative 30 position, but upon movement of the rod 28 toward the left, as viewed in Fig. 1, roller 32 riding on cam surface 33 will rock ring 3| to disengage the clutch elements, all as is more fully shown and described in the before mentioned copending 35 application. The clutch shifting rod is moved to the position shown manually, being provided with a handle 28 for this purpose and, when so moved, the clutch elements are yieldingly moved into driving engagement by springs (not shown). The present stop-mechanism for actuating the clutch and automatically rendering the machine inoperative upon depletion or breakage of any one of the thread ends, comprises a series of detectors, corresponding to the number of thread ends. In the present instance, there are two detectors 34, 35, for the needle thread ends, and two detectors 36, 31, for the looper thread ends. Said detectors are loosely pivoted on a shaft 38 journaled in bearings 39 and mounted on said shaft is a cam member 40 having a knife edge on which is normally supported an arm 41 of a rocking member 42 (Fig. 5). Member 42 which is journaled, and capable of sliding movement, in bearings 43 is provided with a finger or offset end portion 44 adapted to be moved into the path of a pin 45 on a revolving member, preferably cam l6, driven by the drive shaft I4. That is, when arm 4| is supported in its elevated position on knife edge 40, finger 44 of the rock shaft is positioned clear of pin 45, but if said knife edge g itudinally and arm 4| engages said projection 28 and moves rod 28 toward the left in Fig. 1, to disengage the driving clutch.

As mentioned, arm 4| is normally supported on knife edge 40, so that pin 45 cannot engage finger 44 so that the stop mechanism is normally inoperative, but upon breakage or depletion of any one of the thread ends, shaft 38 is caused to rock and displace said knife edge. This is accomplished by the provision of a stop, preferably in the form of a bail-like member 45 secured on shaft 38 by a set screw 41, against which the detectors move if permitted to swing or pivot on said shaft upon depletion or breakage of the thread ends. Preferably, each detector is formed with a hook-shaped free end normally supported on a thread end and thus held against pivotal movement on shaft 38 but if any one of said ends should break or become depleted, the detector for that particular end will swing downward and upon engaging stop 46 will cause shaft 38 to rock and displace knife edge 40 with the result that rock member 42 will turn to position finger 44 in the path of pin 45, and the latter will move member 42 longitudinally so that arm 4| will, in turn, move clutch shifter rod 28 to disengage clutch 21 and render the machine inoperative.

The detectors are preferably positioned on shaft 38 between the two arms 46 of the bail-like stop 46 and said shaft can be made to accommodate any number of detectors by varying the length of said stop. Where the number of detectors is insufficient to occupy the entire space between arms 46*, washers 48 may be interchangeable for the hub portions 49 of said detectors. To remove or replace the washers or detectors it is only necessary to loosen set screw 41 and slide the stop 46 off the end of shaft 38.

What I claimis:

1. The combination with the driving and clutch shifter mechanism of a sewing machine, of stop motion mechanism including a plurality of detectors corresponding tothe number of ends constituting the threads used in the machine, a rock shaft on which said detectors are loosely pivoted, said detectors being supported adjacent one extremity by said thread ends and being free to pivot by gravity on said shaft upon depletion or breakage of said thread ends, each detector being movable independently of the other, a link interposed between said driving and clutch shifter mechanisms, means on said shaft for holding said link in neutral position, and means operable by movement of any one of said detectors for rocking said rock shaft and moving said link holding means to permit said link to move to operative position.

2. The combination with the driving and. clutch shifter mechanism of a sewing machine, of stop motion mechanism including a plurality of detectors corresponding to the number of ends constituting the threads used in the machine, a

rock shaft, said detectorsbeing supported adjacent one extremity on said thread ends and loosely supported on said shaft for pivotal movement upon breakage or depletion of said thread ends,

means associated with said shaft for maintaining said clutch shifter mechanism inoperative, and

means operable by pivotal movement of any one of said detectors independently of the condition or position of the remaining thread ends for rocking said rock shaft and actuating said last-mentioned means to render said shifter mechanism operative.

3. The combination with the driving and clutch shifter mechanisms of a sewing machine, of stop motion mechanism including a plurality of detectors corresponding to the number of ends constituting the threads used in the machine, a shaft on. which said detectors are loosely pivoted, control means mounted on said. shaft for normally maintaining the clutch shifter mechanism inoperative, and means operable by pivotal movement of any one of said detectors for rocking said shaft and actuating said. control means to render said clutch shifting mechanism operative.

4. The combination with the driving and clutch shifter mechanism of a sewing machine, of stop motion mechanism including a plurality of detectors corresponding to the number of ends constituting the threads used in the machine, a shaft on which said detectors are loosely pivoted, controlimeans mounted on said shaft for normally maintaining the clutch shifter mechanism inoperative, and an arm mounted on said shaft engagable by said detectors for rocking said shaft and rendering said clutch mechanism operative.

THOMAS H. DE SPAIN. 

